Center Of Pressure Area Research Articles

Impact of plantar fasciitis on postural control and walking in young middle-aged adults

PurposeTo assess if plantar fasciitis has an impact on postural control and walking pattern from gait analysis across different experimental conditions. MethodsThirty participants (n = 15 with plantar fasciitis) performed 5 different balance tasks on a force platform, and the center of pressure (COP) was computed for postural control analysis. Participants were also asked to walk at 3 different speeds on a gait analysis system to compute the spatial-temporal parameters. Clinical foot measurements (pain, mobility) were also collected through all participants. ResultsClinical foot measurements showed no significant difference between the two groups; except for pain palpation in plantar fasciitis group. Significant differences were observed between the two groups for COP area displacement sway (p < 0.01; d = 0.08) and velocity (p = 0.022; d = 0.04), where the fasciitis group reported poorer postural control than control mainly during more challenging balance tasks (semi-tandem, unipodal). Plantar fasciitis group reported a decrease of gait velocity (p < 0.01; d = 0.12), step length (p < 0.01; d = 0.16) and step width (p < 0.01; d = 0.18) when compared to the healthy group across walking speed tests. ConclusionsIndividuals with plantar fasciitis report poor postural control and changes in walking pattern across three speeds performance.

THE INFLUENCE OF HEIGHT ON TEST-RETEST RELIABILITY OF POSTURAL BALANCE MEASURES IN HEALTHY YOUNG ADULTS

Height is associated with postural balance performance. However, there has been no study on whether the test-retest reliability of the balance performance variables is related to height. The goal of our study was to analyze the effect of body height on the test-retest reliability of center of pressure (COP) variables during natural and feet-together stances in healthy young subjects. Twenty normal young men were classified into the short height group (height range, 163–174[Formula: see text]cm) and the tall height group (height range, 176–184[Formula: see text]cm) with 10 subjects each to investigate the influence of height on test-retest reliability. All subjects performed the static balance test on a commercial force plate in feet-together and natural stance conditions three times. Four variables were calculated from the COP data. COP distance, COP area, COP velocity, and COP mean frequency were selected as the postural balance variables. Intraclass correlation coefficient (ICC) was evaluated for an analysis of the test-retest reliability of each COP variable. In both stance conditions, the COP distance and the COP area in the short height group (ICC = 0.717–0.902) showed better test-retest reliability compared to those in the tall height group (ICC = 0.146–0.688). COP velocity had the highest ICC value in both stance conditions (ICC = 0.744–0.970). Additionally, the short height group showed slightly better reliability in the feet-together stance condition, whereas the tall height group showed slightly higher ICC value in the natural stance condition. These results suggest that height should be considered for a more reliable assessment of repetitive static balance performance. Our findings might be useful for the development of an optimal static balance test protocol regardless of the effect of height.

Time-of-Day Effect on Postural Balance and Its Associations with Menopausal Symptoms in Postmenopausal Women.

Postmenopausal women suffer from postural balance issues. During a 24-hour time span, postural performance undergoes radical changes as influenced by the circadian rhythm. In this study, we aimed to investigate time-of-day effects on postural balance in postmenopausal women and balance relationships with menopausal symptoms. Two groups of women, aged 40-50years, participated in this study: a menopausal group and a control group. We evaluated their postural balance and menopausal symptoms (mood, sleepiness and fatigue) in five sessions over the course of a day: at 06:00 hours, at 10:00, at 14:00, at 18:00 and at 22:00. The results showed that postural balance (center of pressure area (CoParea)) values of postmenopausal women were significantly worse (p < .05) at 22:00. Moreover, at this time-of-day, participants in the menopausal group were more tired, less vigilant and experienced a lower mood. We found negative correlations between postural balance and both mood and fatigue levels. However, there was no time-of-day effect on postural balance, mood, fatigue, and sleepiness among participants in the control group. Thus, time-of-day should be considered a factor to control when assessing postural balance and designing intervention studies for postmenopausal women; and it is important for these women to be cautious of fall risks at night, as they are then less stable than at other times-of-day.

Comparison of the Effects of an Exergame-Based Program with Conventional Physiotherapy Protocol Based on Core Areas of the European Guideline on Postural Control, Functional Mobility, and Quality of Life in Patients with Parkinson's Disease: Randomized Clinical Trial.

Introduction: Impairment of postural control and functional mobility are debilitating symptoms of Parkinson's disease (PD). In addition to limiting performance in activities of daily living, it is associated with a higher prevalence of falls in this population. Particularly, dysfunction in postural control does not respond to dopaminergic replacement therapy, but physiotherapy can improve this outcome in patients with PD. Objective: The aim of this study was to analyze the effects of training based on Kinect Adventures games compared with a conventional physiotherapy protocol based on the core areas of the European physiotherapy guideline in patients with PD on postural control, functional mobility, self-perception of confidence in the balance, quality of life (QoL), lower limb muscle strength, transfer skill and motor function, as well as to observe adherence and safety interventions. Methods: Thirty-eight patients diagnosed with idiopathic PD were randomized into two groups, and performed 14 training sessions, twice a week for 60 minutes. The primary outcome assessed postural control using the Mini-Balance Evaluation Systems Test (Mini-BESTest). The following were evaluated as secondary outcomes: limit of stability; balance functional reserve and center of pressure area by computerized posturography; functional mobility by the Timed Up and Go test; self-confidence in balance through the Activities-specific Balance Confidence scale; QoL through the Parkinson's Disease Questionnaire; lower limb muscle strength by the Five Times Sit-To-Stand test; and motor function by the Unified Parkinson's Disease Rating Scale. Results: Patients completed training sessions with high rates of safety and adherence. After training, there was a significant improvement in postural control, motor function, and QoL. Conclusion: Both interventions proved to be safe, applicable, and effective to improve postural control, QoL, and motor function in patients with PD. However, there was no difference between the effects of Kinect Adventures games and conventional physiotherapeutic protocol in patients with PD. Brazilian Registry of Clinical Trials (RBR-27kqv5).

Changes in Ground Reaction Forces and Center of Pressure Parameters of Paws When Wearing Dog Boots in Dogs.

Dog boots are commonly used as protective footwear against snow, ice, hot sand, road salt, and paw injury. Only a few studies exist in veterinary medicine that capture the impact of dog boot replacements, such as bandages, on ground reaction forces (GRF) in dogs. To our knowledge, no studies have investigated the effect of dog boots on the center of pressure (COP) in dogs. This study investigated changes in the GRF of the whole limb and selected COP parameters of the paws while wearing dog boots in five Labrador Retrievers. After habituation, data were collected by walking and trotting dogs over a pressure platform without boots (control measurement) and under five different test conditions (wearing boots on all limbs, boots on both front limbs, boots on both hind limbs, one boot on the left front limb, and one boot on the right hind limb). The most prominent change was detectable when one boot was worn on the left front limb, with a decrease of peak vertical force (PFz%) in the left front limb at trot which led to a significant difference between both front limbs and a significant increase of PFz (%) in the right hind limb. Additionally, in both tempi, the vertical impulse (IFz%) showed significant differences between the front limbs; in trot, there was also an increase in the right front limb compared with the control. Furthermore, some significant changes in COP parameters were detected; for instance, all test conditions showed a significant increase in COP area (%) at the right front limb during walking compared to the control. Therefore, our results show that wearing the tested dog boots in different constellations seems to have an impact on GRF and some COP parameters.

Visual feedback in the lower visual field affects postural control during static standing

BackgroundThe dorsal parietal visual system plays an important role in self-motion perception and spatial cognition. It also strongly responds to visual inputs from the lower visual field. Postural control is modified in a process called sensory reweighting based on the reliability of available sensory sources. The question of whether visual stimuli presented to either the lower or upper visual field affect postural control and sensory reweighting has not been resolved. Research questionDo visual stimuli presented to the lower and upper visual fields affect postural control and sensory reweighting? MethodsTwenty-nine healthy young adults participated in the study. Four conditions (full visual field, upper visual field, lower visual field, and no optic flow condition) were simulated in a VR environment using a head-mounted display. The optic flow stimuli used were swarms of small white spheres originating from the central point of the visual field, moving radially towards the periphery, and expanding across the scene. Participants were instructed to stand quietly for 50 s under each visual condition. Using force plate signals, we measured the center of pressure (COP) signal in the horizontal plane and calculated its 95 % ellipse area, root mean square (RMS) deviations, the mean velocity, and power spectral density (PSD). ResultsOptic flow in the full and lower visual fields produced significantly smaller 95 % ellipse area and RMS of COP in the anterior-posterior direction compared to optic flow in the upper visual field. Furthermore, the PSD of the lower frequency band (0–0.3 Hz) was decreased and that of higher frequency bands (0.3–1 Hz and 1–3 Hz) was increased for the lower compared to the upper visual field. SignificanceVisual feedback affects static postural control more when presented in the lower visual field compared to the upper visual field.

Visual, Vestibular, and Proprioceptive Dependency of the Control of Posture in Chronic Neck Pain Patients.

Sensory reweighting of postural control was compared in participants with and without neck pain. Center of pressure variables of 60 volunteers, the same in each group, were calculated under four standing conditions: (a)eyes open, neutral head posture; (b)foam interface, eyes open; (c)cervical extension, eyes open; and (d)cervical extension, eyes closed. All center of pressure variables except anterior posterior range/velocity increased significantly in Condition 2 compared with Conditions 1 and 3 (p < .001) and in Condition 4 compared with Conditions 1 and 3. The mediolateral range/velocity and path length in both groups, anterior posterior range in patients, and center of pressure area in the control group were significantly different between Conditions 2 and 4 (p < .001). No overweighting was observed on the vestibular or visual afferents in patients. Compensatory strategies seem to lie within the proprioceptive system.

Effects of light finger touch on the regularity of center-of-pressure fluctuations during quiet bipedal and single-leg postural tasks

BackgroundThe use of extra sources of sensory information associated with light fingertip touch to enhance postural steadiness has been associated with increased attentional demands, whereas the regularity of center of pressure (COP) fluctuations has been interpreted as a marker of the amount of attention invested in posture control. Research questionThis study addressed whether increased attentional demands associated with postural tasks involving light finger touch might be reflected by measures of COP regularity. MethodsThe experiments involved quiet bipedal stance (n = 8 participants) and single-legged stance (n = 14 participants). Each participant was instructed to stand as quietly as possible on a force plate, either touching an external rigid surface (applied force < 1 N, light touch condition), or not (no touch condition). Postural steadiness was assessed by traditional COP measurements (COP Area, RMS, and velocity), whereas the regularity of postural sway was based on estimates of the sample entropy (SaEn) of the COP time series. ResultsTraditional parameters of postural sway and COP regularity (inversely related to SaEn COP measurements) were reduced during the touch conditions as compared to the no-touch conditions, for both bipedal quiet stance and single-legged stance. Decreased COP regularity with light touch was mainly reflected in the direction of the largest postural sway (i.e. in the sagittal plane for bipedal stance and in the frontal plane for single-legged stance). SignificanceThe present results suggest that actively touching an external surface with the fingertip, besides increasing postural steadiness, generated an externally oriented (presumably cognitive-dependent) focus of attention, so that participants invested less attention on the postural task per se (as suggested by increased SaEn), which might be associated with a more “automatic” control of posture.

Comparison of Clinical Balance and Visual Dependence Tests in Patients With Chronic Dizziness With and Without Persistent Postural-Perceptual Dizziness: A Cross-Sectional Study.

BackgroundThe diagnosis of persistent postural-perceptual dizziness (PPPD) is primarily based on medical history taking. Research on the value of clinical balance and visual dependence tests in identifying PPPD is scarce.Objectives(1) to contrast clinical balance and visual dependence tests between PPPD patients, dizzy non-PPPD patients, and healthy persons; and (2) to evaluate whether these clinical tests can help to identify PPPD in patients with chronic dizziness.MethodsConsecutive patients with chronic dizziness (38 PPPD and 21 non-PPPD) and 69 healthy persons underwent Static Balance tests, the Timed Up and Go test, the Tandem Gait test, and the Functional Gait Assessment (FGA). Visual dependence tests included the Visual Vertigo Analog Scale (VVAS), the Rod-and-Disc test (RDT), and postural sway while facing rotating dots. Groups were compared using ANOVA with post-hoc Tukey, or independent samples t-tests. The value of the clinical tests for PPPD identification was evaluated through logistic regression and Partial Least Squares Discriminant (PLS-DA) analyses.ResultsPPPD patients had significantly higher VVAS scores than dizzy non-PPPD patients (p = 0.006). Facing rotating dots, PPPD and dizzy non-PPPD patients had increased postural sway compared to healthy persons (PPPD vs. healthy: center of pressure (COP) velocity p < 0.001, and COP area p < 0.001; but non-PPPD vs. healthy: COP velocity p = 0.116 and COP area p = 0.207). PPPD patients had no significantly increased postural sway compared to dizzy non-PPPD patients. PPPD and dizzy non-PPPD patients also scored significantly worse on balance tests compared to healthy persons (PPPD vs. healthy: for all balance tests p < 0.001; non-PPPD vs. healthy: FGA p < 0.001, for all other tests p < 0.05). Differences were insignificant in balance scores between PPPD and dizzy non-PPPD patients, or in RDT scores between the three study groups. In patients with chronic dizziness, a higher VVAS score was most associated with PPPD [odds ratio 1.04; 95% CI (1.01; 1.07); p = 0.010]. The cross-validated (CV) PLS-DA model with all clinical tests included, had fair discriminative ability (CVerror = 47%).ConclusionPPPD patients were more visually dependent, but did not have worse postural balance compared to dizzy non-PPPD patients. Elevated VVAS scores characterized PPPD most in patients with chronic dizziness.

Pelvic Floor Muscle Strength and the Postural Balance in Middle-Aged Women: A Pilot Study

Aim To investigate if pelvic floor muscles’ (PFMs’) strength is associated with postural balance in middle-aged women. Methods The participants were 22 middle-aged women (age: 57 ± 6 years). They completed a clinical and urogynecological evaluation, PFMs’ strength testing using a perineometer, and balance testing on a force platform. The balance variables analyzed were anteroposterior (AP) and side-to-side (SS) center of pressure (COP) displacement; 95% elliptical COP area (cm2), AP and SS COP displacement median frequency. Results PFMs’ strength was moderately correlated with SS COP displacement and with AP COP median frequency in semi-tandem. Age and educational level affected the relationship between PFMs’ strength and balance. Conclusion PFMs’ strength had the strongest associations with SS COP displacement in eyes-open semi-tandem and AP COP median frequency in eyes-closed semi-tandem. Thus, these results allow us to conclude that there may be some relationship between pelvic floor muscle strength and postural balance in middle-aged women.

Gait and posture are correlated domains in Parkinson’s disease

Establishing a relationship between gait and posture in patients with Parkinson's disease (PD) is essential for PD treatment and rehabilitation. While previous studies have indicated that gait and posture are independent domains in PD, shared neuromechanisms related to gait and posture control and previous studies investigating the relationship between gait and posture parameters in stroke survivors and neurologically healthy older adults have shown a correlated domain. Thus, this study analyzed the relationship of gait and posture domains, primarily through gait temporal sub-phases (i.e., double support and stance phases) and step width. We analyzed the spatial-temporal gait parameters at the self-selected velocity and center of pressure (CoP) during quiet standing of 22 idiopathic PD participants under and without dopaminergic medication conditions. The association between quiet standing and gait variables was assessed through the Spearman test, controlled by age, disease duration, NFoG-Q, and levodopa dosage. In ON medication, CoP area showed a significant correlation with stance phase and total double support; and RMS ML CoP showed a significant correlation with stance phase, total double support, and step width. In OFF medication, CoP area, RMS AP CoP, RMS ML CoP, and ML CoP velocity significantly correlated with stance phase and total double support. By showing the relationship between gait and posture domains in PD, our study adds novel knowledge about the shared gait-posture control, which could collaborate with new approaches during mobility treatment and assessment.

Balance is impaired in symptomatic ankle osteoarthritis: A cross-sectional study

Ankle osteoarthritis (OA) is associated with several physical impairments but investigations into balance impairments in this population are limited. Understanding balance impairments in ankle OA may help inform the management of this condition. Does balance overall performance differ between individuals with symptomatic radiographic ankle OA, asymptomatic radiographic ankle OA and healthy controls? Are there any differences in mediolateral or anteroposterior balance, or confidence to perform balance tasks between these groups? Ninety-six volunteers (31 symptomatic radiographic ankle OA, 41 asymptomatic radiographic ankle OA and 24 healthy controls) completed six static balance tasks: bilateral stance on a firm surface, bilateral stance on foam, and tandem stance, all performed with eyes open and closed. Centre of pressure (COP) data were collected using force plates. Confidence to perform each balance task was collected using an 11-point numerical rating scale. Compared to controls, participants with symptomatic radiographic ankle OA had greater COP area when standing on a firm surface, foam and in tandem with eyes closed (all p < 0.05) and greater total COP sway in both firm surface and tandem stance conditions (p < 0.04). Participants with symptomatic ankle OA had greater COP area (p < 0.04) and total COP sway (p = 0.01) than those with asymptomatic ankle OA during tandem stance. Total COP sway and area were similar between asymptomatic ankle OA and control participants. Some differences in mediolateral and anteroposterior balance were identified between groups. Individuals with symptomatic ankle OA had lower confidence to perform the tandem stance eyes closed task compared to controls. Balance impairments and decreased balance confidence were identified in those with symptomatic radiographic ankle OA compared to asymptomatic individuals with and without radiographic ankle OA. This suggests that balance deficits in ankle OA may be related to symptoms, rather than radiographic evidence of disease.

The effects of pain and a secondary task on postural sway during standing.

Pain impairs available cognitive resources and somatosensory information, but its effects on postural control during standing are inconclusive. The aim of this study was to investigate whether postural sway is affected by the presence of pain and a secondary task during standing. Sixteen healthy subjects stood as quiet as possible at a tandem stance for 30s on a force platform at different conditions regarding the presence of pain and a secondary task. Subjects received painful stimulations on the right upper arm or lower leg according to a relative pain threshold [pain 7 out 10 on a Visual Analog Scale (VAS) - 0 representing "no pain" and 10 "worst pain imaginable"] using a computer pressurized cuff. The secondary task consisted of pointing to a target using a head-mounted laser-pointer as visual feedback. Center of Pressure (COP) sway area, velocity, mean frequency and sample entropy were calculated from force platform measures. Compared to no painful condition, pain intensity (leg: VAS=7; arm VAS=7.4) increased following cuff pressure conditions (P<.01). Pain at the leg decreased COP area (P<.05), increased COP velocity (P<.05), mean frequency (P<.05) and sample entropy (P<.05) compared with baseline condition regardless the completion of the secondary task. During condition with pain at the leg, completion of the secondary task reduced COP velocity (P<.001) compared with condition without secondary task. Pain in the arm did not affect postural sway. Rather, postural adaptations seem dependent on the location of pain as pain in the lower leg affected postural sway. The completion of a secondary task affected postural sway measurements and reduced the effect of leg pain on postural sway. Future treatment interventions could benefit from dual-task paradigm during balance training aiming to improve postural control in patients suffering from chronic pain.

Gait and Balance Biomechanical Characteristics of Patients With Grades III and IV Hallux Rigidus

Patients with hallux rigidus (HR) tend to develop a characteristic alteration in walking to lessening pain and compensate for the limited range of motion at the first metatarsophalangeal (MTP1) joint that might be affected balance and gait. The goal of this study was to perform an integrated biomechanical description of gait and balance of symptomatic patients with either grade as III or IV HR in comparison with healthy subjects. Eleven patients (7 men) with HR (60 ± 7 years, 1.60 ± 0.07 m, and 70 ± 13 kg) and 16 (7 men) healthy subjects (70 ± 8 years, 1.66 ± 0.10 m, and 74 ± 14 kg) were included. Subjects performed 2 tasks: walking (5 trials of straight walking for at least 6 meters) and bipedal quiet standing for 30 seconds. For these 2 tasks the following variables were measured: range of motion of the MTP1 joint, plantar pressure distribution during the stance phase of walking, and the postural sway during quiet standing. Plantar pressure was measured in up 15 walking trials with a mat pressure sensor. The MTP1 joint range of motion for flexion/extension during walking was significantly smaller for the patients with HR than for the control group (HR: 14 ± 8°, control: 44 ± 5°; t(17) = -9.7, p < .001). The forefoot plantar pressure distribution among different regions of the foot in patients with HR was not statistically different than the control group, but there was a tendency of higher pressures in the lateral metatarsal heads (p = .06). As description of the postural sway during quiet standing, the center of pressure area was not different between HR and the control group (p > .05). Decreased MTP1 joint range of motion for flexion/extension during walking in symptomatic high-grade HR patients can be associated with higher pressure in the lateral metatarsal heads while the impact on postural sway is not affected.

Time-of-day effects on the postural control and symptoms in women with rheumatoid arthritis

ABSTRACT The present study was designed to assess time-of-day effects on postural balance and symptoms of rheumatoid arthritis (RA) patients. A total of 15 American College of Rheumatology functional class I and II RA patients and 15 healthy controls aged between 45 and 55 (mean age: 50 ± 3) years of age voluntarily participated. We conducted a case-control, repeated-measures in design study. Postural balance, axillary temperature, pain intensity, fatigue, and sleepiness were measured during five test sessions at 06:00, 10:00, 14:00, 18:00, and 22:00 h. Participants were randomized to the order of test sessions, and each session was separated by >36 hours to minimize/eliminate learning effects. Center of pressure area (CoParea) (p < .001), pain (p < .01), and sleepiness (p < .05) values were significantly higher at 06:00 and 22:00 h compared to 10:00, 14:00, and 18:00 h in the RA group. Fatigue significantly increased (p < .05) at 22:00 h in comparison to 10:00, 14:00, and 18:00 h in the RA group. Axillary temperature was significantly (p < .001) lower at 06:00 and at 22:00 h compared to 10:00, 14:00, and 18:00 h in the RA group. In the control group, there were no significant time-of-day difference in fatigue, but axillary temperature was significantly lower (p < .01) at 06:00 h compared to 10:00 h, 14:00, 18:00, and 22:00 h, sleepiness values were significantly higher (p < .05) at 06:00 and 22:00 h compared to 10:00, 14:00, and 18:00 h, and revealed CoParea values were significantly (p < .05) higher at 06:00 h compared to 14:00 h. Finally, in the RA group, significant correlations were found between values of CoParea and pain (r = 0.47; p < .001), sleepiness (r = 0.39; p < .01), fatigue (r = −0.46; p < .001), and also axillary temperature (r = −0.35; p < .001). Multiple linear regression analysis further indicated that in the RA group, time-of-day variation in postural balance was predicted collectively by that in pain and fatigue (30.7%) (R2 = 0.307; F = 11.53; p < .001). Our results first suggest that time-of-day significantly affects postural balance, axillary temperature, pain intensity, fatigue, and sleepiness in RA patients and second that the temporal variation observed in pain, fatigue, and somnolence are concomitant with that observed in postural balance. Abbreviations: RA: Rheumatoid arthritis; H&O questionnaire: Horne and Ostberg questionnaire; PSQI: Pittsburgh sleep quality index; HAQ: Health assessment questionnaire; SF-36: the short form-36; WOMAC: Western Ontario and McMaster Universities Osteoarthritis Index; CoP: The Center of foot Pressure; CoParea: The Center of foot Pressure area; VAS: The Visual Analogue Scale; KSS: Karolinska Sleepiness Scale

Low-Back Pain and Knee Position-Related Differences on Postural Control Measures During a One-Legged Stance in Athletes.

Chronic low-back pain (CLBP) may be associated with changes in postural balance in athletes as poor postural control during sports practice. To compare the postural control of athletes with and without CLBP during 2 one-legged stance tasks and identify the center of pressure (COP) cutoff values to determine the main differences. Designed: A cross-sectional study. Laboratory of functional evaluation and human motor performance. A total of 56 male athletes, 28 with and 28 without CLBP (mean age = 26y). The one-legged stance with knee extension and with the knee at 30° flexion tasks were measured and analyzed on a force platform. The participants completed three 30-second trials (30s of rest between each trial). The COP parameters: the area of COP, mean COP sway velocity in both the anteroposterior and mediolateral directions, and total COP displacement were computed, and a receiver operating characteristics curve analysis was applied to determine the group differences. Athletes with CLBP had poorer postural control (P < .01) in both tasks. The 30° knee flexion reported more postural instability than the knee extension for all COP parameters (a large effect size d = 0.80).The knee extension cutoffs identified were >7.1 cm2 for the COP area, >2.6 cm/s for the COP sway velocity in the anterior-posterior direction, and >3.2 cm/s for the mediolateral direction. Whereas, the 30° knee flexion cutoffs were >10.9 cm2 for the COP area, >2.9 cm/s for the COP sway velocity in the anterior-posterior direction, and >4.1 cm/s for the mediolateral direction. Both measures showed enough sensitivity and specificity (ie,area under the curve = 0.88 in and 0.80, respectively) to discriminate both groups. The athletes with CLBP had poorer postural control than the healthy athletes and obtained specific cutoff scores from the COP values.

Effects of Attentional Focus on the Corticospinal Excitability during Anticipatory Postural Adjustments in Dart Throwing

Attentional focus can affect motor performance and learning. It is known that external focus (EF) which concentrated on the movement outcome leads better performance and efficient motor output rather than internal focus (IF) which concentrated on one's body movement. It remains unclear whether the attentional focus modulates the corticospinal excitability during anticipatory postural adjustments (APA). In the present study, we using transcranial magnetic stimulation (TMS) examined the excitability changes in the primary motor cortex (M1) during dart throwing with different attentional focuses. We hypothesized that the APA duration and magnitude is different between EF and IF conditions, and the corticospinal excitability of lower leg muscle increases in the phase of APA, while the extent to which modulation is different between conditions. Fifteen healthy volunteers were asked to perform dart throwing with the dominant hand with a visual cue under the EF condition (focus on the flight trajectory of the dart) and IF condition (focus on the elbow angle of the dominant hand). The participants performing the tasks stood on a force plate with the legs closed, and we measured the displacement of center of pressure (COP). Electromyography (EMG) was recorded from the anterior deltoid, triceps brachii (TB), tibialis anterior (TA), and soleus muscles. Because the EMG of TA muscle was clearly observed from about 300 ms before the EMG onset of TB muscle (agonist muscle of throwing), TMS was applied over the hotspot of TA muscle in the contralateral M1 at the timings of the visual cue, 0 to 100 ms prior to the EMG onset of TA muscle, and the EMG onset of TB muscle. The distance from the bulls-eye was significantly shorter with EF than that with IF. Neither the difference in the total length of COP and rectangle area nor in the APA duration and magnitude was observed between EF and IF conditions. The motor evoked potential (MEP) amplitude in the TA muscle at -100ms, -50 ms, TA onset, and TB onset significantly increased in comparison with that at control in both conditions. In particular, MEP at -50 ms, TA onset, and TB onset were significantly larger with EF than those with IF, whereas there were no significant differences in MEP at visual cue and -100 ms between EF and IF conditions. Our results demonstrate that the excitability of corticospinal projections to the lower leg muscle increases immediately prior to a ballistic movement of the upper limb. It suggests that, by changing the attentional focus the cortical contribution to the postural control is modulated which may improve motor performance and efficacy of the movement execution.

Comparison of gait recovery patterns according to the paralyzed side in stroke patients: An observational study based on a retrospective chart review (STROBE compliant).

Gait rehabilitations have been abundantly performed for post-stroke patients, because gait is the most important factor for the return of post-stroke patients to daily life. However, conventional uniform gait rehabilitations tend to be tedious and reduce motivation. The aim of this study was to contribute to the development of personalized rehabilitation of gait by identifying differences in gait recovery pattern according to the paralyzed side of post-stroke patients.The gait analysis was performed on stroke patients who are right-handed and can walk independently. We retrospectively analyzed the results of pelvic movements and displacement of center of pressure (COP) during gait using corresponding equipments. To show the difference of gait recovery pattern according to the paralyzed side, we divided subjects into two groups, right (n = 19) and left (n = 20) hemiparesis group. The measured variables were as follows: tilt, obliquity, and rotation symmetries of pelvis; area, velocity, and lateral symmetry of COP.First, in the left hemiparesis group, obliquity (P < .01) and rotation (P < .01) symmetries of the movement of the pelvis were significantly improved in the follow-up compared to the initial gait analysis. In the right hemiparesis group, tilt (P < .001), obliquity (P < .001), and rotation (P < .05) symmetries were significantly improved in the follow-up compared to the initial gait analysis. Second, COP area and COP velocity values in the follow-up were significantly smaller than those in the initial gait analysis in the left (P < .001, P < .05) and right (P < .001, P < .01) hemiparesis groups. The positive value of lateral symmetry increased, although not a significant difference statistically, as walking ability improved in both groups. In the correlation analysis among variables obtained using Treadmill, there were significant positive linear relationships between the lateral symmetry and the COP area (P < .05), and between the COP velocity and the lateral symmetry (P < .001) of the follow-up gait analysis in the right hemiparesis group.It was confirmed that the gait recovery pattern differs according to the paralyzed side of post-stroke patients and the role of the intact side, such as moving the COP to the intact side, is important for the improvement of gait function in both groups.This study was registered with the Clinical Research Information Service (CRIS) of the Korea National Institute of Health (NIH), Republic of Korea (KCT0002984) and was approved by the Institutional Review Board (IRB) of the WKUGH (WKIRB [2018-25], November 28, 2018).

Stabilometric analysis as a cognitive function predictor in adults over the age of 50: A cross-sectional study conducted in a Memory Clinic

BackgroundThe aging process reduces adaptive balance responses. Two-thirds of older adults with cognitive problems suffer at least one fall every year, a rate three times higher than that observed in older adults without dementia. This cross-sectional study aims to analyze the relationship between balance and cognitive status in adults older than 50 years. MethodsIndividuals over the age of 50, who attended a Memory Clinic, were evaluated for balance changes using stabilometry, with analysis of the center of pressure (CoP). The following CoP parameters were assessed using an S-Plate pressure platform: 1) sway length, 2) sway area, and 3) anteroposterior and laterolateral sway (width, mean deviation, and speed). The individuals were evaluated with eyes open and closed for 30 s in each test. The Montreal Cognitive Assessment (MoCA) was used to assess cognitive status. ResultsEighty-seven subjects participated in the study. The average age was 67.8 years, 81.4% were female, and the average MoCA score was 19.8 points. Greater CoP oscillation was observed in the eyes closed condition, demonstrating greater postural imbalance. We found a significant and direct effect of MoCA score on the CoP area in the eyes open condition. Conclusion: The results suggest that stabilometric analysis may be a predictor of cognitive function.

The Effects of Static Stretching On Dynamic Postural Control During Maximum Forward Leaning Task

The purpose of this study was to determine how the application of static stretching to ankle plantar flexors affects postural control during maximum forward leaning. Twenty-six volunteer males (age 21.4 ± 1.2 years) were randomly assigned to stretching and control conditions. Participants conducted 5-min stretching on a stretch board for the stretching condition and were kept standing for 6-min for the control condition. Before and after intervention, the range of motion (ROM) at ankle dorsiflexion and the center of pressure (COP) excursion during maximal forward leaning were determined. Mean anteroposterior COP position, COP velocity and COP areas were calculated to compare the change in postural control. After stretching, ROM was significantly increased. During maximal forward leaning after stretching, both COP position and velocity showed significant increases compared to before stretching. Moreover, COP position and velocity in the stretching condition were significantly higher than in the control condition after stretching. No significant differences were found in COP area before and after stretching. Five-minute stretching increased not only ROM but also the anterior limit of stability while maintaining posture and led to faster COP shift than before stretching. These results indicate that static stretching would improve dynamic postural control as well.